Interlagos is darker. I think the closest thing to LMB is Ultramarine Blue, which was on the original pre-release list of colors. I guess they cancelled it (UB) when they decided the light metallic blues were the hot color to offer with the M-sport pack.
You can order the leather interiors (black, etc.) with the M-pack. Check out any of the Euro BMW websites and 'build your vehicle.' Personally, I think the alcantara/cloth interior is the bomb -- I love its looks and functionality, no sliding around, cool in summer, warm in winter. Goes great with LMB and the alu trim. Probably tough to clean though -- anyone with experience?